The present invention generally relates to dot pattern generating systems, and more particularly to a dot pattern generating system which generates scaled down characters with an arbitrary interval to be printed or displayed by use of one kind of a character generator.
In a conventional printing apparatus, there are basically two methods of generating and printing a scaled down character. According to a first method, a character generator exclusively for generating a scaled down character is provided with respect to all of the desired reduction factors of the character. On the other hand, according to a second method, a ratio between a feeding speed of a printing head and a number of times a printing element to be driven is changed for a normal printing and a scaled down printing in a serial printer. In other words, when the ratio for the normal printing is assumed to be 1:1, the ratio is changed to n:m for the scaled down printing, where n is smaller than m, so as to print scaled down characters of various reduction factors by use of a single kind of character generator. For example, the second method of printing is disclosed in a Japanese Laid-Open Patent Application No. 58-127281. However, according to the first method, it is necessary to provide a memory having an extremely large memory capacity in order to print the characters with the desired reduction factor, and this method is undesirable from the economical point of view. On the other hand, according to the second method, the dot density becomes too dense and the discrimination of the character becomes difficult when printing a character such as a chinese character having a dense dot density because the dot pattern is compressed and printed within a small area when printing the scaled down character. Further, according to the second method, the feeding speed of the printing head for the scaled down printing must be reduced to n/m the feeding speed for the normal printing, and the processing capability becomes poor. Moreover, according to the second method, the printing noise increases considerably in the case of an impact type printer.